Sensing arrangement for stored information concerning positioning of a mechanical element



Jan. 14, 1958 H. GRT'rRUP Y 2,820,216

SENSINGv ARRANGEMENT FOR STORED INFORMATION CONCERNING POSITIONING 0F A MECHANICAL ELEMENT meduarch 14, 195e A ATTORNEY United tates Patent O SENSING- ARRANGEMENT FOR STORED INFOR- MATION CONCERNING POSITIONING F A MECHANICAL ELIIMEN'Il Helmut Grttrup,.Birkenfeld,. Wnrttemberg, Germany, .as-- signor to International' Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application March 14,. 195.6,.Serial No..571',58 Claims priority, application Germany March 19,1955

7` Claims.' (CL-340-174) This invention relates tovl improvements for a sensing arrangementV for storedzinformation concerning the physical position of amechanical element and more particularly regarding the positioning of mechanical elements in recording devices.

rihe physical position of a mechanical element has hitherto been indicated both mechanically and electrically. The electrical indication has been achieved by means of selsyn devices,.potentiometer follow-upssystems, capacitive or inductive bridge tapping arrangements and the like. The earlier form of position indicating devices included mechanically actuated electrical switches which by their condition, denoted the corresponding position of the mechanical elementwith which they were associated.

The disadvantage ofthelast mentioned arrangement lay in the relatively high amount of energy required to move the mechanical element and the switch contact and in the susceptibilityof'the switch arrangement to foulup by reason of dirty contacts or mis-adjustments thereof. lf information regarding the position of a mechanical element required storage over a relatively long period of time, it wasrconsidered necessary in the prior art tolemploy additional auxiliary storageelements for usein'connection with the sensing arrangement.

The invention has for one of its aims an arrangement for indicating the position of a mechanicalelement by the utilization of 'magnetic storage elements ofhigh remanence` in which the magnetic flux is maintained over relatively long periods after magnetization, the storage elements adapted to store information magnetically concerningthe position of the related mechanical element Without the intervention of auxiliary storage elements.

According to a feature of the invention, there is associated lwith the mechanical element regardingwhosel position information'is to be-stored, a magnetic shieldtwhich is co-movable with thefmechanical element and whichshield influencesl theexcitation of at least'one magnetic storage element. Tubular members of a material of high magnetic remanence are preferably used as magnetic storage elements, while a correspondingly sub-divided tube of magnetically soft material is employedlas a shield.

According to a further feature of the invention, a group of such magnetic storage elements is linked with the mechanical member'concerning whose'position information is to be stored and the shield is sodesigned that dey pending on'the position ofthe mechanical member, only one of the magnetic storage elements can be energized by a common electromagnetic exciting means.

According to yetanother featureof-the invention, the magnetic storage elements are so arranged that by the corresponding design of the magneticv shield and depend ing upon the position of the mechanical element, a predetermined combination of the magnetic storage elements' can be energized by thecommon exciting means; the combination including vthe production of a signal code made of a predetermined number'of units such as marking or spacing units, etc;

2,820,216 Patented Jan. 14, 1958 Although thedisclosed embodimentsA of the invention are. appliedv to aV device for the sensing of the position of movable elements associated with oilice recording machines", it is to be clearly understood thatA the invention is not. limited to: thistnarrow field, but may be applied wherever the problem of indicating the position of a mechanical member is presented. The invention also' lends itself to a novel system of telemetering. The advantage of a sensing, arrangement according to this invention rests primarily in the fact that both the. sensing arrangement and the storage facilityv are formed in an integral or single unit. It is also possible according to thevinvention tocaterto therequirement that mechanical members and magnetic shield'members associated therewith'y areffree'toaccept atn'ew setting after magnetization of the-magnetic storage elements without the destruction of the storage of they preceding setting. Further advantages Which accrue from theinvention are to be realized from it'ssmall dimensions, its low power requirements and low susceptability tofaulty operation due to the accumulation of dirt or mis-adjustment.

Thc'aboveementioned andother features and' objects of this invention and theV manner ofv attainingthem will becomermoreapparentand theinvention itself will be best understood, byy ref'erence'toV the'following description ofanembodime'nt of the invention takenin conjunction withl the accompanyingdrawings, wherein:

Fig. lafisV a schematic representation partly in section= toindicate a rst physical. position of a mechanical element;

Fig. 1b is a schematicrepresentation partly inV section of thee'mbo'dinrent'shown in Fig. la with the magnetic shieldinglelement-Y in a position toisolat'e` the storage element from-the'outputfdetecting circuit, thereby to indicate anothery position of tlie mechanical element;

Fig. 2 isa schematiclrepresentation partlyin section of' anotherform of my'invention which enables the evaluation' o'f anyoneoften'discretepositions'of a mechanicaly member;

Fig. 3 isa schematic representation partly insection of another form'of myfinvention which enables the productionofa telegraph' codedepending upon the positioning of a'single associated mechanical element.

Referring now'to Fig. la, there is shown in section a tube of insulating material 1. Tube l is nonLmagnetc andcarriesaround the outer surface thereof a magnetic storage element Z-Shaped in the form of a ring'and made of a materialy having-high magnetic remanence disposed coaxially around-the tube 1. l further'provide a shield carrying element 6 `made of non-magnetic material. The tube 6 hasa smaller diameter than tube It with which it isco-axial; Disposed about'the periphery of a portion of the tube 6'] provide a magnetic shielding portion 7 and which portion consists of a magnetically soft material'. lt will be noted that the portion 7 encompasses only a portion of' the axial length of the tube 6. The tube 6 is providedwith a coupling 8 adapted to be attached to--the movable mechanical element 8a by means of a suitable linlr'tlb.y The mechanical element 3a may be movable in the direction of the arrow A1l by suitable means, not shown since such means form no part of this invention. The showingin Fig. lb shows the mechanical element 8a in its upward yposition whereas the showing in Fig. la discloses the mechanical element 8a in its lower or downward position. The element Sa may be moved in the di# rection of arrow A2 in Fig. 1b.

Returning again to Fig. la thereis further* shown an ing is-shown in -a mostfelementary"schematic forni' it bei ing intended that the ield which surrounds the wire 3 will set up a magnetic ux in a eld surrounding the wire at right angles thereto. There is further provided a second winding 9 which is in flux producing relation with the magnetic storage element 2 and is connected to battery by means of contact 10. It will be observed that the direction of the windings 3 and 9 respectively is carried to opposite terminals of the battery 5 so that the electron flow through coils 3 and 9 will be opposite. There is further shown an output winding 11 coupled between magnetic storage element 2 and a utilization circuit 12. The utilization circuit 12 is shown as a rectangle and may be of any known type.

The operation of the device thus far disclosed is as follows:

Assume that prior to the start of the storage process, the magnetic storage element 2 is so magnetized that its flux runs counter-clockwise. The tube 6 with its shield portion 7 may be moved -into the position shown in Fig. 1b by the movement of the mechanical element 8u; thereafter the switch 4 is closed causing electron flow through the line 3. The shield 7 however prevents the ield generated by the line 3 from having any elect on magnetic storage element 2. If however, the switch 4 were to be closed while the shield 7 is in the position shown in Fig. la, the counter-clockwise flux in magnetic storage element 2 which was initially present will now be overcome and a clockwise flux will be established in the storage element 2, and an output pulse will appear in line 11 having a first polarity. It will be recalled that storage element 2 is of high magnetic remanence and therefore the clockwise flux created by line 3 will be maintained. Once the storage element 2 has been magnetized in a particular direction, the tube 6 and of course its associated mechnical ele ment 8a may move freely without atiecting or destroying the stored magnetic charge in element 2.

The closure of contact 10 will cause a ux to be set up in storage element 2 opposite to that created by the closure of switch 4 and this change will be reflected in an output pulse having a second polarity and which is generated in the output coupling line 11 and the utilization -circuit 12. In Fig. 1b since the storage element 2 was magnetized so that the flux direction was counterclockwise and since the shield 7 prevented the line 3 from altering this ux pattern, the closure of contact 10 will have no effect on storage element 2 since the line 9 will tend to magnetically energize storage element 2 in a counter-clockwise direction. No output will be passed to utilization circuit 12 via the output line 11 since it is elementary that no output current is developed in a coil unless a change of magnetic ux is presented thereto. Thus the position of the tube 6 and the mechanical e1ement 8a with which it is associated is characterized by the presence or absence of an output pulse upon the successive closure of contacts 4 and 10 as above described.

The uX change which occurs in the storage element 2 and the consequent current impulse developed in the output line 11 may be arranged to be responsive only to a change brought by the closure of contact 10 by known means such for instance as a rectifier in series with the output line 11 so that an output pulse will be generated when the storage element 2 is magnetized in a first direction only, it being obvious that no output pulse will be derived when the storage element 2 is biased back to a starting or counter-clockwise position by line 9. The contacts 4 and 10 may be cyclically operated in the order mentioned when it is desired to sense the position of the element 8a.

The embodiment shown in Fig. 2 discloses structure similar to that shown in Figs. 1a and lb with certain modifications. The tube 6 is provided with two magnetic portions 7a and 7b with a gap between the two portions indicated as 6a. Surrounding the tube 6 and tixed with respect to the movement thereof, are ten spaced magnetic storage elements 2a 2j each having its associated output line 11a 11j. Each output line is connected with its individual utilization device (not shown) similar to the device 12 shown in Figs. la and lb. In the Fig. 2 showing the mechanical element 8a is not shown in order to maintain the drawing uncomplicated but it will be understood that the tube 6 is drawn in a direction transverse to the storage elements 2a. All other elements of the showing in Fig. 2 otherwise correspond to those shown in Fig. 1 and serve the same function. The carrier 1 is also eliminated from the showing in Fig. 2 but it will be understood that each of the storage elements 2a 2j are spacedly mounted from each other. The line 3 is common to each of the storage elements 2a 2j as is the line 9. It will be observed that the gap 6a will permit but a single storage element 2a 2j to be subject to the influence of the line 3 and that by moving the tube 6 in either a rig'nt or a left hand direction in Fig. 2 will enable another of the storage elements 2a 2j to be exposed to the energization flux of line 3 without the shielding effect of portions 7a or 7b. In the showing in Fig. 2 storage element 2e is in position to be acted upon by line 3 through the gap 6a. It will be understood that the gap 6a on tube 6 must be transportable from a position where it is in register with any of the elements 2a 2j in order to record the ten discrete possible positions of the tube 6.

The operation of the structure of Fig. 2 is essentially similar to that described in connection with Figs. 1a and lb namely that prior to the storage process the storage elements 2a 2]' are magnetized in a counter-clockwise direction. After the movement of the tube 6 and the positioning of the gap 6a in register with a storage member 2a 2j indicative of the direction of degree of movement thereof, closure of the switch 4 and energization of the line 3 will magnetize the single storage element and a clockwise ilux direction is derived. After the switch 10 is closed only that storage element will undergo a flux reversal which was in register with the gap 6a, and an output will be derived from its corresponding outputline 11a 11].

Fig. 3 discloses another embodiment of my invention which is utilized for storing information regarding the position of a mechanical member and deriving from a plurality of storage members a code combination. The apparatus consists of a group of five tubes 6b 6f each coupled to a common mechanical link 10x, and which link is in turn adapted to be moved by the mechanical element (not shown) with which it is to be associated. Each of the tubes 6b 61 is provided with portions 7c 7f and is provided with a plurality of gaps between the portions similar to the gap 6a in Fig. 2. It will be observed that the length of the corresponding portions 7c 71 of the various tubes 6 are different and are purposely so. Each of the tubes has associated therewith its individual storage element 2k 20; each of the storage elements is provided with its individual output line 11k 11o as in the Fig. 2 showing. Similarly the excitation line 3a controlled by the switch 4a is provided with live parallel branches extending through each of the live tubes 6b 6] so that upon closure of switch 4a the magnetic iield is set up within each of the tubes 6b f and which eld will be effectively shielded from the magnetic storage elements 2k 2o by the particular portions 7c 7]c except Where a gap is in register with its cooperating storage element. There are provided a plurality of windings 9e each coupled to a different one of the magnetic storage elements 2k 2o and each of which is adapted to be sequentially energized by means of the wiper contact 10a when said wiper contact contacts corresponding terminals 97' 9j, respectively. By means of this sequential operation the condition of each of the elements 2k 2o may be sampled. Thus information may be applied to the storage structure in simultaneous fashion and read out sequentially to produce a train of impulses and may be derived as mark and space impulses in a printing telegraph code after the addition of the necessary start and stop impulses. In operation, a predetermined amount of movement of the link x will result in a rst code element being formed by the excursion of wiper 10a over the terminals 9j 9g. A further movement of the link 10x will bring a new combination of portions 7d in various positions vis-a-vis, the magnetic storage elements 2k 2o and upon a new excursion of the Wiper 10a another code combination is formed, and

so on.

The embodiments above described have outlined movement of mechanical elements in a transverse direction with respect to the storage elements. However, the invention is not limited to such transverse motion and it is within the scope of this invention to provide storage of information regarding the position of mechanical elements which rotate with respect to the magnetic storage elements. The configuration of the magnetic storage elements is not necessarily limited to an annulus, but may also be of any suitable shape.

While I have described above the principles of my invention in connection with specic apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

What is claimed is:

1. A device of the class described comprising magnetic storage means of high remanence, output means coupled to said storage means, first means for applying to said ,storage means a magnetic ux having a rst polarity, second means for applying to said storage means a magnetic flux having a second polarity, movable shielding means adapted to be selectively interposed between said storage means and said second flux application means, and means for sequentially operating said first and said second flux application means whereby said storage means undergoes no ux change when said shielding means is in shielding relation with said storage means and undergoes a flux change when said shielding means is out of shielding relation with said storage means.

2. A device as claimed in claim l, wherein said storage means comprises an annulus of magnetic material and said output means comprises a utilization circuit inductively coupled to said annulus.

3. A device as claimed in claim 2, wherein said shielding means comprises a cylinder of magnetically soft materia 4. A device as claimed in claim 2, wherein said storage means comprises a plurality of spaced annular storage elements, and said output means comprises a plurality of utilization circuits, one for each of said elements, said rst and said second ilux application means common to each of said elements, said shielding means comprising a tube of non-magnetic material having mounted coaxially thereon a pair of tubes of soft magnetic material, said pair of tubes longitudinally spaced from each other to define a gap therebetween, the width of said gap equivalent to a distance required to shield all but a single one of said elements from said second flux application means, said tube adapted to be selectively positioned whereby said gap may be placed in opposition with any of said elements.

5. A device as claimed in claim l, wherein said storage means comprises a plurality of annular elements, said shielding means comprises a plurality of non-magnetic tubes, one for each of said elements, and having a coating of soft magnetic material thereon, said material having a plurality of variable width gaps along the length of said tube, corresponding gaps on each of said tubes being of dilerent widths, each tube mechanically coupled for movement with the other.

6. A device as claimed in claim 5, wherein said second ux application means comprises a plurality of parallel energizing circuits, each circuit adapted to be inductively coupled to a dilerent one of said elements, said first ux application means comprising a plurality of parallel energizing circuits, each circuit inductively coupled to a different one of said elements, and switch means for sequentially energizing said last named circuits.

7. A device as claimed in claim 1, wherein said shield means is mechanically coupled to an element whose physical position is to be sensed.

References Cited in the le of this patent UNITED STATES PATENTS 2,403,889 Di Toro July 9, 1946 2,647,252 Moore July 28, 1953 2,712,601 Reinwald July 5, 1955 

